Electromagnet.



UNITED STATES PATENT OFFICE.

EDVARD B. ELLICOTT, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE XVESTERNELECTRIC COMPANY, OF SAME PLACE.

ELECTRO MAG NET.

SPECIFICATION forming part of Letters Patent No. 683,451, dated October1, 1901.

Application filed May 26, 1900.

T all whom it may concern:

Be it known that I, EDWARD B. ELLicoTT,

a citizen of the United States, residing at Chicago, in the county ofCook and State of Illinois, have invented a certain new and use-- fulImprovement in Electromagnets, (Case No. 11,) of which the following isa full, clear, concise, and exact description.

lily invention relates to an electromagnet, and has for its object toprovide an improved structure which will permit of the ready removal ofthe magnetizing coil or helix and the substitution of another in itsplace.

My invention is especially valuable as applied to relays, which aresubject to frequent burn-outs-as, for instance, relays used inconnection with a lire-alarm-telegraph system.

It is often thought wise to dispense with safety-fuses and suchprotecting devices in re-alarm-telegraph systems in order that thepossibility of failure in the transmission of an alarm through thebreaking down of a fuse or protector may be obviated. It is consideredbetter policy to replace a burned-out relay-coil occasionally than tointroduce such uncertain elements as safety-fuses into the system. Forthis reason the magnet-coils of relays used in these systems arefrequently destroyed by heavy currents which are accidentally thrown onthe line. l/Vhen the magnet-coils of relays in such systems are burnedout, it is of course necessary that they be replaced immediately inorder that the system may not be crippled for any appreciable length oftime, and it has been my purpose to construct relays and otherinstruments in which electromagnets are employed with these requirementsin View.

Briefly, myinvention consists in mounting the pole-pieces fixedly withrelation to the other parts of the instrument upon the baseplate of theinstrument and winding the magnetizing helix or coil upon a separatedetachable core. Preferably the pole-pieces are made the terminals ofthe circuit in which the magnet is to be included, andthe two ends ofthe detachable core of the magnet are electrically and magneticallyinsulated 5o from one another and form the terminals of the helix.Thumb-screws may be provided Serial lo-18,078. (No model.)

in each pole-piece to fasten the core in place. The two ends of the coreform the terminals of the magnet-coil, and the coil is thus connected incircuit by the very act of securing it in place upon the instrumentwithout the necessity of changing any of the wiring or connections. Thetwo ends of the core are preferably separated magnetically as well aselectrically to lessen the inertia or reluctance 6o of the magneticcircuit of the instrument, so that it will respond more quickly tosignals.

I will describe my invention more particularly by reference to theaccompanying drawings, which illustrate a polarized relay constructed inaccordance therewith.

Figure 1 is a plan View of the relay, the magnetiZing-helix and corehaving been removed. Fig. 2 is an elevation of the instrument with thecore and its helix in place, 7o and Fig. 3 is a similar view in verticalsection.

The same parts are indicated by the same letters of reference whereverthey are shown.

The polarized relay illustrated in the drawings is of a type adaptedespecially for use in electrical tire-alarmtelegraph systems and induplex or quadruplex telegraphy. A centrally-pivoted armature a ismounted upon the metallic standard a', which is secured to 8o theinsulated base b. The armature is adapted to vibrate in a horizontalplane, and two pole-pieces c c are mounted upon the plate af',with thearmature between them. A, tongue or extension a2 is provided uponone endof 83 the armature, and contact-posts d3 d3 are mount-ed upon the basein position to be engaged by contact-points carried by the tongue as itswings to one side orthe other. The polepieces c c are formed withupwardly-projecting 9o portions c c', adapted to be united by thecorepiece d, which carries the magnetizing coil or helix c. Thecore-piece d, while mechanicallya unitary structure, is made in twoparts electrically and magnetically separated from 9 5 one another. Thetwo parts of the core are joined together by a brass screw f, whichengages with iber bushings screwed into each half of the core-piece, asshown most clearly in Fig. 3. The core d is secured in place beroo tweenthe two standards or pole-pieces c c by means of thumb-screws g g,pass1ng through Vss the upper portions of the pole-pieces and into the ends ofthe core, the ends of the core being bored and tapped to receive thescrews.

Metallic end plates h h are mounted one on each end of the core CZ, andthe vends of the magnetizing coil or helix e are connected,respectively, with these end plates. When the core is in position,therefore, the polepieces c c are thus electrically connected with theends of the coil by way of the end plates h h, the two halves or ends ofthe core CZ, and the screws g g. These pole-pieces are insulated fromthe metallic standard a, which carries the relay-armature, and arewired, respectively, to the binding-posts k 7c, mounted upon thebase-plate b of the instrument. These binding-posts thus form theterminals of the magnet-coil and may be connected in circuitaccordingly.

The armature a is connected through its metallic standard cd with thetwo bindingposts Z Z, either of which may be used as the terminal of thearmature. The contact-posts a3 CL3 are wired to the binding-posts Zl Z.The pair of binding-posts Z Z on either side of the instrument may formthe terminals of a loy cal circuit to be controlled by the switch-congpole-pieces to unite the same, means for de tacts of the relay.

The armature a in the relay shown is a permanent bar-n'lagnet,` therelay being thus l polarized. The contact-screws in the posts a3 a3should be so adjusted that the armature i will not touch the ends of thepole-pieces c c to prevent short-circuiting the magnet-coil. 'lhe sidesof the armature a or the ends of the pole-pieces may also be coveredwith insulating material for the same purpose.

Should the helix e become burned out by the passage of an excessivecurrent, the thumb-screws may be loosened, the injured coil instantlyremoved, and a perfect onesubstituted in its place without loss of timeand without the necessity of disturbing the wiring 'or connections ofthe instrument.

The two halves of the core-piece d are separated magnetically, as wellas electrically, for the purpose of introducing a break into themagnetic circuit of the instrument to make the magnet respond morequickly-that is, to decrease the magnetic inertia ofthe instrument.

My invention will be found of great value in connection with anyinstruments whose coils it may be desired to change frequently.

I claim as new, and desire to secure by Letters Patent, the following:

l. 'Ihe combination with xedly-mounted pole-pieces c c electricallyseparated from one another' and adapted to be connected in an electriccircuit, of an armature for said pole-piece nounted within the magneticfield thereo a core-piece CZ anda magnetizing-helix carried upon saidcore, the ends of said core being electrically insulated from oneanother and connected, respectively,with the ends of themagnetizing-helix, and screws g g adapted to secure the core detachablyto the pole-pieces, substantially as and for the purpose set forth.

2. The combination with the base-plate b, rof a pair of magnetpole-pieces c' c lxedly mounted thereon and electrically insulated fromone another, said pole pieces being adapted to be connected in anelectric circuit to form the terminals thereof, an armature for saidpole-pieces, a magnet-core CZ adapted to unite said pole-pieces, meansfor detachably securing the core and pole-pieces together, whereby saidcore may be easily removed, and a helix e carried by said core, the endsof said helix being adapted to he brought in electrical connection withthe pole-pieces c' c', respectively, when the core and helix are securedin position, substantially as set forth.

3. The combination with a pair of polepieces c' c' electricallyseparated from one another, and adapted to be connected in an electriccircuit to form terminals therefor, a corepiece CZ formed in two partsor sections joined end to end and separated magnetically andelectrically from one another, said core being adapted to be placedbetween said pair of tachably securing the core in place between saidpole-pieces, and a magnetizing coil or helix surrounding said core andcarried thereby, the ends of said helix being electrically connected,respectively, with the two parts or sections of the core, as set forth.

4. An electromagnet comprising a helix e and a core CZ, about which saidhelix is wound, said core being formed in two parts or sections joinedend to end and separated magnetically and electrically from one another,the two parts or sections of said core being electrically connected,respectively, with the ends of the magnet-winding or helix, as setforth.

5. An electromagnet comprising a helix e and a core d, about which saidhelix is wound, said core being formed in vtwo sections joined end toend, but insulated electrically from each other, and end plates h hmounted upon the ends of said core and electrically connected,respectively, with the terminals 'of the helix, the ends of the corebeing bored and tapped, substantially as and for the purpose set forth.

6. An electromagnet comprising a helix e, and a core d upon which saidhelix is wound, said core being formed in sections joined end to end andinsulated electrically from one another, the sections of said core beingconnected, respectively, with the ends of the magnetwinding or helix, asset forth.

In witness whereof I hereunto subscribe my name this 24th day of April,A. D. 1900.

EDWVARD B. ELLICOTT.

Witnesses: j

JOHN B. PORTER, A. M. KINZIE. y f/ IOO IIO

